1. What is the difference between passive and active transport?
Passive transport is diffusion across a membrane with no energy investment, while active transport requires energy.
2. What are the three types of solutions?
The three types of solutions are isotonic, hypotonic and hypertonic.
3. What is the first law of thermodynamics?
According to the first law of thermodynamics, the energy in the universe is constant.
Five main facts from the reading:
1. Transport proteins may facilitate diffusion across membranes.
2. Exocytosis and endocytosis transport large molecules across membranes.
3. Cells transform energy as they perform work.
4. Energy cannot be created or destroyed, it can only be transferred.
5. Chemical reactions either release or store energy.
Diagram:
This diagram shows different passive transport of molecules. The first row shows a solution separated from pure water by a membrane. The second row illustrates the important point that two or more substances diffuse independently of each other.
Link: http://teacherwanafizah.blogspot.com/2009/03/biology-passive-transport-and-active.html
Summary:
The introduction talks about some sea animals who have the ability to become invisible and protect themselves or hunt. They do this by turning on some lights, by chemical reactions.
The next section of the chapter taught us that membranes are fluid mosaic of phospholipids and proteins. They exhibit selective permeability, which is, they allow some substances to cross more easily than others. Membranes form spontaneously, a critical step in the origin of life. Passive transport is diffusion across a membrane with no energy investment. Diffusion is the tendency for particles of any kind to spread out evenly in an available space, moving from where they are more concentrated to regions where they are less concentrated. Osmosis is the diffusion of water across a membrane. Water balance between cells and their surroundings is crucial to organisms. The term tonicity describes the ability of a solution to cause a cell to gain or lose water. The three types of solutions are: isotonic, hypotonic, and hypertonic. The control of water balance is called osmoregulation. Transport proteins may facilitate diffusion across membranes. When a protein makes it possible for a substance to move down its concentration gradient, the process is called facilitated diffusion. Cells expend energy in the active transport of a solute against its concentration gradient. In active transport a cell must expend energy to move a solute against its concentration gradient - that is, across a membrane toward the side where the solute is more concentrated. The cell's energy molecule ATP supplies the energy for most active transport. Exocytosis and endocytosis transport large molecules across membranes. Cells transform energy as they perform work. They are three kinds of energy: kinetic energy, potential energy, and chemical energy. There also two laws, which govern energy transformations: the first and the second laws of thermodynamics. Thermodynamics is the study of energy transformations that occur in a collection of matter. Chemical reactions either release or store energy. An exergonic reaction is a chemical reaction that releases energy. ATP shuttles chemical energy and drives cellular work.
Key Terms:
1. Passive transport - diffusion across a membrane with no energy investment.
2. Osmosis - the diffusion of water across a membrane.
3. Active transport - a cell must expend energy to move a solute against its concentration gradient.
4. Endocytosis - a transport process that is the opposite of exocytosis.
5. Exocytosis - a cell uses the process of exocytosis to export bulky materials such as proteins or polysaccharide.
6. Phagocytosis - cellular eating.
7. Pinocytosis - cellular drinking.
8. Energy - the capacity to perform work.
9. Kinetic energy - the energy of motion.
10. Chemical energy - a term that refers to the potential energy available for release in a chemical reaction.
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